The design and synthesis of 9-phenylcyclohepta[d]pyrimidine-2,4-dione derivatives as potent non-nucleoside inhibitors of HIV reverse transcriptase

Access to 1,3-oxazine-2,4-diones/1,3-thiazine-2,4-diones via organocatalytic CO2/COS incorporation into allenamides

Organocatalyzed [4 + 2] annulation of CO₂/COS with allenamides is firstly reported to synthesize 1,3-oxazine-2,4-diones and 1,3-thiazine-2,4-diones in moderate to excellent yields under mild reaction conditions. The catalytic potential of a series of Lewis base CO₂ and COS adducts are particularly noted for this process, which features high regio- and chemo-selectivity, step-economy, facile scalability, and easy product derivatization. This study offers the potential for the application of organocatalytic systems for CO₂ and COS chemical transformation.

Exploring the generation and use of acylketenes with continuous flow processes

The generation and use of acyl ketenes under continuous flow reaction conditions is reported. Several reaction classes of these reactive intermediates have been studied. Under zero headspace conditions, a ketone exchange process is possible between volatile ketones. The process can be readily scaled to deliver gram quantities of product.

Synthesis, anti-angiogenic and DNA cleavage studies of novel N-(4-methyl-3-((4-(pyridin-3-yl)pyrimidin-2-yl)amino)phenyl)piperidine-4-carboxamide derivatives

A series of novel N-(4-methyl-3-((4-(pyridin-3-yl)pyrimidin-2-yl)amino)phenyl)piperidine-4-carboxamide derivatives 10(a-f), 12(a-c) and 14(a-c) were synthesized and characterized by FTIR, ¹H-NMR, mass spectral and elemental analysis. The efficacy of these derivatives to inhibit in vivo angiogenesis was evaluated using chick chorioallantoic membrane (CAM) model and their DNA cleavage abilities were evaluated after incubating with calf thymus DNA followed by gel electrophoresis. These novel piperidine analogues efficiently blocked the formation of blood vessels in vivo in CAM model and exhibited differential migration and band intensities in DNA binding/cleavage assays. Among the tested compounds 10a, 10b, 10c, 12b, 14b and 14c showed significant anti-angiogenic and DNA cleavage activities compared to their respective controls and the other derivatives used in this study. These observations suggest that the presence of electron donating and withdrawing groups at positions 2, 3 and 4 of the phenyl ring of the side chain may determine their potency and as anticancer agents by exerting both anti-angiogenic and cytotoxic effects .

6-[(2-Methyl-phen-yl)sulfan-yl]-5-propyl-pyrimidine-2,4(1H,3H)-dione

In the title pyrimidine-2,4-dione derivative, C14H16N2O2S, the dihedral angle between the six-membered rings is 77.81 (10)°. The mol-ecule is twisted about the Cp-S (p = pyrimidine) bond, with a C-S-C-N torsion angle of -59.01 (17)°. An intramolecular C-H⋯S hydrogen bond generates an S(5) ring motif. In the crystal, bifurcated acceptor N-H⋯O and C-H⋯O hydrogen bonds generate inversion-related dimers incorporating R 2 (1)(9) and R 2 (2)(8) loops. These dimers are connected into a chain extending along the a-axis direction by a second pair of inversion-related N-H⋯O hydrogen bonds, forming another R 2 (2)(8) loop. The crystal structure is further stabilized by weak inter-molecular C-H⋯π inter-actions, generating a three-dimensional network.

5-Propyl-6-(p-tolyl-sulfan-yl)pyrimidine-2,4(1H,3H)-dione

In the title pymiridine-2,4-dione derivative, C₁₄H₁₆N₂O₂S, the dihedral angle between the six-membered rings is 66.69 (10)°. The mol­ecule is twisted about the C_p—S (p = pyrimidine) bond, with a C—S—C—N torsion angle of −19.57 (16)°. In the crystal, adjacent mol­ecules form inversion dimers through pairs of strong N—H⋯O hydrogen bonds, generating an R₂²(8) ring motif. The dimers are connected into chains extending along the c-axis direction through additional N—H⋯O hydrogen bonds.

Synthesis, antifungal activity, and QSAR studies of 1,6-dihydropyrimidine derivatives

INTRODUCTION

A practical synthesis of pyrimidinone would be very helpful for chemists because pyrimidinone is found in many bioactive natural products and exhibits a wide range of biological properties. The biological significance of pyrimidine derivatives has led us to the synthesis of substituted pyrimidine.

MATERIALS AND METHODS

With the aim of developing potential antimicrobials, new series of 5-cyano-6-oxo-1,6-dihydro-pyrimidine derivatives namely 2-(5-cyano-6-oxo-4-substituted (aryl)-1,6-dihydropyrimidin-2-ylthio)-N-substituted (phenyl) acetamide (C1-C41) were synthesized and characterized by Fourier transform infrared spectroscopy (FTIR), mass analysis, and proton nuclear magnetic resonance ((1)H NMR). All the compounds were screened for their antifungal activity against Candida albicans (MTCC, 227).

RESULTS AND DISCUSSION

Quantitative structure activity relationship (QSAR) studies of a series of 1,6-dihydro-pyrimidine were carried out to study various structural requirements for fungal inhibition. Various lipophilic, electronic, geometric, and spatial descriptors were correlated with antifungal activity using genetic function approximation. Developed models were found predictive as indicated by their square of predictive regression values (r(2pred)) and their internal and external cross-validation. Study reveals that CHI_3_C, Molecular_SurfaceArea, and Jurs_DPSA_1 contributed significantly to the activity along with some electronic, geometric, and quantum mechanical descriptors.

CONCLUSION

A careful analysis of the antifungal activity data of synthesized compounds revealed that electron withdrawing substitution on N-phenyl acetamide ring of 1,6-dihydropyrimidine moiety possess good activity.

1-Eth-oxy-methyl-5-methyl-9-phenyl-6,7,8,9-tetra-hydro-1H-pyrimido[4,5-b][1,4]diazepine-2,4(3H,5H)-dione

The title compound, C(17)H(22)N(4)O(3), comprises a 1,4-diazepine ring in a twist-boat conformation fused to a pyrimidine ring. The dihedral angle between the pyrimidine and phenyl rings is 80.8 (1)°. The crystal packing features N-H⋯O and C-H⋯O hydrogen bonds.

Synthesis of novel 6-phenyl-2,4-disubstituted pyrimidine-5-carbonitriles as potential antimicrobial agents

New series of 6-phenyl-2,4-disubstituted pyrimidine-5-carbonitriles namely, 2-substitued thio-6-phenyl-3,4-dihydro-4-oxopyrimidine-5-carbonitriles (5a-d, 6, 7a-d, 8), 2-(4-chlorobenzylthio)-4-chloro-6-phenylpyrimidine-5-carbonitrile (9), 2-(4-chlorobenzylthio)-4-arylthio-6-phenylpyrimidine-5-carbonitriles (10a-d) and 2-(4-chlorobenzylthio)-4-arylamino-6-phenylpyrimidine-5-carbonitriles (11a-d) was synthesized and tested for in vitro activities against a panel of Gram-positive and Gram-negative bacteria and the yeast-like pathogenic fungus Candida albicans. Compounds 5b, 5c, 6, 7a, 7b, 7c, 9 and 11a displayed marked antibacterial activity particularly against the tested Gram-positive bacteria, while compounds 6, 7c, 7d and 9 were moderately or weakly active against C. albicans.

The design and synthesis of N-1-alkylated-5-aminoaryalkylsubstituted-6-methyluracils as potential non-nucleoside HIV-1 RT inhibitors

Novel compounds 1a-u, which can be considered as hybrid analogues of MKC-442 and pyridinon, have been synthesized and evaluated as inhibitors of HIV-1 reverse transcriptase (HIV-1 RT). Starting from 6-methyluracil 2, 1-alkylated-5-bromomethyl-6-methyluracils 8 was prepared in four steps by hydroxymethylation, etherification, N-1 alkylation, and bromination. Finally, compounds 1a-u were achieved in the displacement of 5-bromomethyl group by nucleophiles with amino compounds. Some of compounds 1a-u showed potent inhibitory activity against HIV-1 RT. The most active compounds showed activity in the low micromolecular range with IC(50) values (IC(50) 0.82-5.09 microM) comparable to that of nevirapine (IC(50) 10.60 microM). The biological testing results are in accordance with the docking.